There are tens of billions of neurons in your brain. Groups of them fire in a certain sequence when you see or otherwise experience an object, and those sequences and firing patterns are encoded as memories of that object. Networks of cells not only record memories, though, they also encode instructions for regulating the level of hormones, for example, or the instinctual response to something that looks like a predator.

Each network can be understood on its own, each has a particular role. But how do the multitude of interconnections between trillions of nerve cells and the feedback loops they generate produce the mysterious, emergent property that we experience as consciousness?

An explanation for consciousness has been on the wishlist of many a researcher. Partly it has been held up by something that the philosopher David Chalmers referred to as the "hard problem" – assuming we can understand everything about how the brain works and we know how the brain generates behaviour and perceptions, we would still not be able to explain how we experience these things.

Consciousness is one of the last outposts of pure mystery in our understanding of the brain. Sure, there is plenty to learn about how the brain's physiology controls our bodies, emotions and enables thoughts. But where "we" exist in our bodies, how we develop that sense of self and how it can be explained in terms of the activity of mere cells in our brain – all of that is still a mystery.